[ABSTRAC]Several rich uppermost Maastrichtian sites containing dinosaur bones near Arén and Serraduy (Huesca,Spain) have been discovered. The Arén dinosaur sites include six fossiliferous levels from the top of the ArénSandstone to the middle part of the Tremp Formation. The Aren levels contain remains of hadrosaurids (one species,at least), one big theropod and three small theropods. The Serraduy dinosaur includes one site from theTremp Formation with sauropod remains. The discovery of this dinosaur association shows that the dinosaurs survivedup to the latest Maastrichtian, at least in Western Europe.